Obesity and Risky Sexual Behavior Are Linked in Young Women

Young, overweight women are more likely to engage in risky sexual behaviors and are at significantly higher risk for sexually transmitted infections than their more slender peers, a new study by the Yale School of Public Health has found. The paper is published online in the journal AIDS and Behavior.

The study looked at 704 young mothers from New Haven and Atlanta. Researchers examined the influence of a woman’s body mass index (BMI) on how likely she is to engage in sexually risky behavior (e.g., having unprotected sex or having multiple or casual partners) and on the likelihood of having a sexually transmitted infection (STI).

They found that overweight mothers between the ages of 14 and 25 are nearly 80 percent more likely to have an STI than their peers who were not overweight and 64 percent more likely to engage in risky sexual behavior. Meanwhile, the study found that young mothers who are classified as obese, rather than just overweight, are less likely to have STIs than their normal weight peers.

“Researchers tend to focus on one health problem or another, without thinking about how health behaviors may relate and how common risk and social factors play a role across a wide spectrum of health outcomes,” said lead author Trace Kershaw, an associate professor at the School of Public Health and a researcher at the Yale Center for Interdisciplinary Research on AIDS (CIRA). “Given the impact of obesity and sexual risk on young individuals, we need to develop comprehensive prevention programs that target multiple risk behaviors and outcomes.”

Even though obesity and sexual risk are two of the most pressing public health issues among young people in the United States today, there has been relatively little research on how the issues are linked, he said.

While the findings are significant, the reasons for these relationships are not as well understood, Kershaw said. These differences occurred despite overweight women having similar amounts of protected and unprotected sex. “It is possible that it is not differences in behavior that is causing increased STIs in overweight women, but the type of sex partner. Overweight women had riskier partners, which may be putting them at increased risk,” he said.

Other researchers involved in the study are Jeannette Ickovics, a professor at the School of Public Health; Jessica Lewis, an associate professor at the Yale School of Medicine; and Urania Magriples and Anna Arnold, research associates at CIRA. The research was funded by the National Institutes of Mental Health.